In bar displays, the prior art systems generally are mechanical and consist of an electro-mechanically driven tape similar to a motion-picture projector with the scale viewed through a slot-type window. The display driven by a motor is subject to wear and shock vibration and thus, suffers from poor reliability and high maintenance attendant with such mechanical drives.
Also existing known displays utilizing incandescent lamps, while arranged to be individually lighted so as to present either a bar or a dot type scale, no attempt has been made to provide such lights with a means to respond to ambient light conditions, i.e., less light output under a low light ambient condition such as at night and much more light under high light ambient conditions such as in daylight. Further, no attempt has been made heretofore to provide a means of controlling the amount of power utilized by the bar display.
Accordingly, it is an object to this invention to provide a bar display which has the following advantages:
Utilization of less power to light a full display,
Utilization of a modular concept to allowing varying display bar lengths,
Extended life of the display because of the ability to control the use of the lights in the display,
Diversity of presenting a single segment or a full bar display,
Control the visibility under various ambient light conditions, and finally,
Ability to present a color display as well as provide a display with small size and low weight.